Hello. Both the 2014 and the 2010 versions of the FR 3.5 have the problem that you can refuel them during a pitstop by selecting a pitstop and an attached refuel amount to it in the setup-screen, but at the same time there is no refueling option in the on-track pitmenu. This either means that the refuel-option is wrongly missing in the pit-menu, or the refuel option in the setup-screen shoudn't be available on this cars and is wrongly activated. I suspect it is the latter, because there is also a bug in which you will get randomly added 30l of fuel (default value) during a pitstop, even if you have no pitstops defined in the setup-screen.
Asked this a few times as well, no answer. also we can only assign one pitstop, not 2 or 3. which limits strategy very much.